A network appliance is a processing system that may be connected to a network to provide service to other devices over the network. A file server, or filer, is an example of a network appliance. A filer is a form of storage server which provides file storage and file access to remote clients that request access to the data storage. Another type of storage server, which may be implemented as an appliance, is one which provides clients with block-level access to stored data, rather than file-level access. Such a server can be used in a storage area network (SAN), for example, to provide an interface between clients and mass storage devices.
Filers, other storage servers, and other types of appliances must be reliable to prevent data loss and to provide prompt and accurate data service to clients. If there is a fault with the appliance, the appliance may cease operating and any data maintained by the appliance may become inaccessible to local or remote users. It is therefore advantageous to quickly resolve any fault with an appliance to make the appliance available and reduce system downtime.
To facilitate diagnosis of faults and other management functions, an appliance such as a filer may include a console port, through which the appliance can output status information and data regarding the activities of the appliance (hereinafter collectively called “administrative data”), to a separate administrative console. The administrative data may include system messages generated by the firmware and operating system (OS) of the appliance. For example, when the appliance is booting, the firmware may output messages indicating that certain components (e.g., memories, processors, interfaces) have been tested, and what the results of those tests are. Other administrative data could be outputted by the operating system, for example, messages during operation indicating that a certain memory has experienced an error, or that a certain component (e.g., network interface) has been activated. Administrative data also could include reports on the activities of memories and attached storage such as hard drives, or could list attempted and successful remote accesses to the appliance. The administrative data report the activities of the appliance such that a system administrator could diagnose an error or monitor the appliance by referring to the administrative data.
The appliance may output the administrative data in the form of console logs that indicate the activities of certain systems of the appliance. A local administrative terminal (or console) may be connected to the console port using a serial cable, to receive the administrative data and to perform other management functions on the appliance. The local administrative terminal may use the administrative data to monitor activity on the appliance. Multiple administrative terminals may be connected through a terminal concentrator, which may also be connected through a local area network (LAN) or wide area network (WAN, such as the Internet) to allow remote access of the administrative data. The terminals connected through the console port can receive real-time status information about the appliance.
A remote management device may be incorporated into an appliance. The remote management device is a separate processing system physically integrated into the appliance that continues to operate independent of any error that may disable the appliance. The remote management device allows a remote user to remotely access certain aspects of the appliance when the appliance is not otherwise available. For example, the remote management device allows a remote user to make configuration changes if necessary to make the appliance functional. The remote management device also allows a remote user to intercept the administrative data outputted by the console port of the appliance.
Diagnosing an error condition that causes a service disruption of a network appliance such as a filer may require inspection of the administrative data. However, in the known prior art, if the appliance is inoperable, the administrative data are no longer generated, and the appliance cannot be remotely accessed. Further, previously generated administrative data streams may be useful when diagnosing error conditions. Therefore, what is needed is a way to access administrative data of an appliance even when the appliance is inoperable, and a way to store and remotely access the stored administrative data.